Popular swimming spots for sunseekers have been closed due to the low quality of waters in the area.
Three south Dublin hot spots are being affected by "overflow discharges of wastewater".
The recent heavy rainfall caused the overflow at multiple wastewater treatment facilities and pumping stations in Dublin bay.
And due to this, Dun Laoghaire-Rathdown County Council has prohibited bathing at Seapoint, Sandycove and Forty Foot.
A statement said: "Having assessed the impact of the wastewater discharges and carried out visual inspections of bathing areas in DLR.
"And acting with the advice of the HSE, Temporary Bathing Prohibition Notices are being put in place with immediate effect, as a precaution, at Seapoint, Sandycove and Forty Foot bathing areas, pending results from testing of water quality at these locations.
"Sampling of these locations has taken place today and results are expected to be available in 3 days."
The ban will cause frustration to those looking to take a dip in the area, as Met Eireann is forecasting temperature of up to 27C on Thursday and Friday.
The notices will remain until conditions return to normal.
The statement added: "Notices warning bathers and swimmers not to enter the water will be put up at the affected bathing areas.
"These temporary prohibition notices will remain in place until water conditions return to normal and sampling results are clear."
